Seat suspension

Abstract

A seat suspension that includes at least one beam spring that extends across a seat pan. In one preferred embodiment, a pair of such springs is carried by the pan. The springs preferably differ in compliance from one another and from a mesh load supporting grid that is connected to each spring. One such arrangement produces a suspension of progressive construction that enables the seat to handle a wide range of shocks, bumps, jolts, and vibration of varying frequencies and magnitudes.

1. A vehicle seat suspension comprising:
 a seat base having a pair of spaced apart retainers; 
 a beam spring carried by the retainers; 
 a seat occupant load supporting suspension webbing of a flexible load bearing fabric carried by the beam spring and underlying a seat occupant supporting surface of the vehicle seat; 
 a bearing carried by a portion of the beam spring received in each one of the retainers, each bearing disposed between the beam spring and an adjacent portion of the seat base; 
 wherein the webbing is pre-tensioned; 
 wherein each one of the retainers comprises (a) a land formed by part of the seat base on which a portion of the beam spring adjacent a corresponding end of the beam spring is supported, and (b) a retainer bar or finger formed by part of the base that overlies a portion of the beam spring at or adjacent the land; 
 wherein the land of one of the retainers is spaced from the land of the other one of the retainers defining a recess therebetween enabling deflection of a portion of the beam spring unsupported by the lands during suspension operation; and 
 wherein the beam spring and bearings are configured to provide a plurality of stages of deflection during suspension operation. 
 
     
     
       2. The vehicle seat suspension of  claim 1  wherein the seat base is a molded plastic seat base with one of the retainers integrally formed in one part of the seat base and the other one of the retainers integrally formed in another part of the seat base. 
     
     
       3. The vehicle seat suspension of  claim 1  wherein each one of the retainers comprises an upraised abutment adjacent the land and spaced from the part of the base overlying the corresponding portion of the beam spring received in the retainer against which a portion of the beam spring can abut. 
     
     
       4. A vehicle seat comprising:
 (a) a seat pan; and 
 (b) a suspension assembly engaged with the seat pan, the suspension assembly including at least one elongate beam spring secured across the seat pan and flexible in a first direction and a supporting member secured across the seat pan and flexible in a second direction different than the first direction; and 
 wherein the seat pan includes a first pair of aligned recesses and a second pair of aligned recesses spaced from the first pair of recesses, and wherein the suspension assembly includes a first beam spring extending between the first pair of recesses, and a second beam spring extending between the second pair of recesses, and the supporting member extending between the first beam spring and the second beam spring and attached thereto. 
 
     
     
       5. The seat of  claim 4  wherein the supporting member is formed of a mesh grid. 
     
     
       6. The seat of  claim 4  wherein the first beam spring has a spring rate different than the spring rate for the second beam spring. 
     
     
       7. The seat of  claim 4  wherein the first beam spring has a length different than the second beam spring. 
     
     
       8. The seat of  claim 4  wherein one beam spring is less compliant than the other beam spring. 
     
     
       9. The seat of  claim 4  wherein the seat pan is comprised of plastic, wherein one recess of each one of the first and second pair of aligned recesses is disposed on one side of the seat pan and the other recess of each one of the first and second pair of aligned recesses is disposed on the other side of the seat pan, and wherein the supporting member comprises a pre-tensioned webbing made of a flexible, elastomeric and load bearing material. 
     
     
       10. The vehicle seat suspension of  claim 4  wherein the supporting member comprises an elastomeric load bearing mesh secured under pre-tension to the first and second beam springs, wherein at least one of the first and second beam springs comprises a leaf spring, and wherein the seat pan comprises a molded plastic seat base. 
     
     
       11. A vehicle seat suspension comprising:
 a seat base having a pair of spaced apart retainers; 
 a first beam spring carried by the retainers; 
 a seat occupant load supporting suspension webbing of a flexible load bearing fabric that is pre-tensioned and carried by the first beam spring and underlying a seat occupant supporting surface of the vehicle seat; 
 a second beam spring carrying the suspension webbing that is disposed rearwardly of the first beam spring and that extends generally parallel to the first beam spring; 
 wherein the seat base has a front and a rear with the first beam spring disposed in a sideways orientation relative to the seat base and disposed adjacent or along the front of the seat base; and 
 wherein the first beam spring is longer than the second beam spring. 
 
     
     
       12. The vehicle seat suspension of  claim 11  wherein the suspension webbing is attached to the seat base adjacent or along the rear of the seat base. 
     
     
       13. The vehicle seat suspension of  claim 11  wherein the suspension webbing is pre-tensioned such that the suspension webbing is elongated at least two percent with no load present and elongates no more than fifteen percent when under load during suspension operation. 
     
     
       14. The vehicle seat suspension of  claim 11  wherein the first beam spring is less compliant than the second beam spring. 
     
     
       15. The vehicle seat suspension of  claim 11  wherein the first beam spring has a spring rate lower than the second beam spring. 
     
     
       16. The vehicle seat suspension of  claim 11  further comprising a seat cushion having a seat occupant supporting surface, wherein the seat cushion overlies at least a portion of the suspension webbing and the first beam spring, and wherein the seat cushion is supported by at least the suspension webbing and the first beam spring. 
     
     
       17. A vehicle seat suspension comprising:
 a seat base molded of plastic having a pair of spaced apart retainer arrangements integrally formed therein; 
 an elongate member received in one retainer arrangement that comprises an elongate beam spring; 
 a plurality of bearings each disposed between the beam spring and the one retainer arrangement; 
 a load bearing suspension webbing comprised of a flexible elastomeric load bearing fabric or mesh that is pre-tensioned when attached to the beam spring and the other retainer arrangement, the suspension webbing extending from the beam spring to the other retainer arrangement; 
 a seat cushion having a seat occupant supporting surface with the seat cushion overlying the suspension webbing and supported by the suspension webbing; and 
 wherein the beam spring and bearings provide a plurality of stages of deflection during suspension operation. 
 
     
     
       18. The vehicle seat suspension of  claim 17  wherein the one of retainer arrangements is constructed and arranged to orient the elongate member transversely relative to the seat base so the elongate member extends from or adjacent one side of the seat base to or adjacent another side of the seat base. 
     
     
       19. The vehicle seat suspension of  claim 18  wherein the one of the retainer arrangements comprises a first retainer pocket integrally formed in one side of the seat base and a second retainer pocket integrally formed in the other side of the seat base with one end of the elongate member received in the first retainer pocket and the other end of the elongate member received in the second retainer pocket. 
     
     
       20. The vehicle seat suspension of  claim 17  further comprising a second elongate member with one of the first and second elongate members disposed along a front of the vehicle seat base and the other one of the first and second elongate members disposed rearwardly of the one of the first and second elongate members with the first and second elongate members spaced apart so that the suspension webbing underlies substantially the entire seat occupant supporting surface. 
     
     
       21. A vehicle seat suspension comprising:
 a seat cushion having a seat occupant supporting surface; 
 a seat base molded of plastic having a plurality of spaced apart retainer arrangements integrally formed therein; 
 a first elongate beam spring carried by one of the retainer arrangements; 
 a second elongate beam spring carried by the other one of the retainer arrangements; 
 a suspension webbing comprised of a flexible load bearing fabric or mesh attached to the first and second elongate beam springs extending therebetween, the suspension webbing underlying substantially the entire seat occupant supporting surface; 
 wherein one of the first and second beam springs has a spring rate or compliancy less than the other one of the first and second beam springs; and 
 wherein the one of the first and second beam springs having the lesser spring rate or compliancy is disposed along or adjacent a front of the seat occupant supporting surface. 
 
     
     
       22. A vehicle seat suspension comprising:
 a seat base molded of plastic having a plurality of spaced apart retainer pockets formed therein; 
 an elongate beam spring received in the retainer pockets; 
 a suspension webbing comprised of a flexible load bearing fabric attached to the beam spring and extending outwardly therefrom supporting a load from a seat occupant; 
 wherein each one of the beam spring retainer pockets comprises a land formed of a portion of the seat base upon which part of the beam spring is supported and a finger or bar formed of another portion of the seat base that overlies the beam spring adjacent the land; 
 a bearing adjacent each land that is attached to the beam spring and disposed between the beam spring and seat base in the vicinity of the land; and 
 wherein the bearings and the beam spring provide a plurality of stages of deflection during suspension operation.